A downhole packer may be run into a wellbore in a “collapsed” state. Once in a desired position in the wellbore, the packer may be actuated radially-outward into an “expanded” state. In the expanded state, the packer may seal an annulus in the wellbore between a tubular and the wellbore wall or between an inner tubular and an outer tubular. This may separate the annulus into a proximal portion and a distal portion and prevent fluid flow therebetween.
Generally, packers include a mandrel having a sealing element positioned on the outer surface thereof. The sealing element is configured to actuate from the collapsed state to the expanded state. The mandrel may be connected with upper and lower tubular members by a threaded, pin-and-box, connection such that the tubular members and the packer form a “string.” This assembly may be suitable in cases where standard size threads are employed. However, specialty or otherwise non-standard threads are sometimes employed for the tubular members. As such, the threads on the mandrel of the packer may not be sized to engage the corresponding threads on the upper and/or lower tubular members. In such instances, a separate packer, with the correct size threads, or an adapter sub, is needed. What is needed is a packer that is configured to engage the tubular members in the string, e.g., notwithstanding the use of non-standard thread sizes in the tubulars.